Final answer:
Episodic memory is about personal experiences ('what, where, when') while semantic memory involves facts and general knowledge, processed in different brain areas.
Step-by-step explanation:
The factor that distinguishes an episodic memory from a semantic memory is that episodic memory is a type of declarative memory that contains information about events we have personally experienced, known as autobiographical memory. It is detailed, context-rich, and encompasses the 'what, where, and when' of an event. In contrast, semantic memory refers to knowledge about words, concepts, and language-based knowledge and facts, which are typically reported as facts rather than stories. Semantic memory doesn't involve recalling personal experiences but rather general knowledge that a person knows.
For example, remembering your last birthday celebration, with all the surroundings, emotions, and events, is an episodic memory. On the other hand, knowing the definition of psychology or the first African American president of the United States is semantic memory. These types of memory are stored and processed in different areas of the brain, with episodic memory particularly dependent on the hippocampus and related medial temporal structures for long-term storage.